Predictive Value of HPV Testing in Self-collected and Clinician-Collected Samples Compared with Cytology in Detecting High-grade Cervical Lesions.

Abstract

Self-sampling has become an attractive proposition now that human papillomavirus (HPV) primary testing is being incorporated into cervical cancer screening programs worldwide. We compared predictive values of HPV testing based on self- and physician-collected samples, and cytology, in detecting high-grade cervical intraepithelial neoplasia (CIN). The Cervical And Self-Sample In Screening (CASSIS) study enrolled 1,217 women ages 16-70 years prior to scheduled colposcopies. Vaginal specimens were self-collected using the validated HerSwab device. Cervical specimens were collected by gynecologists. Specimens were tested for presence of high-risk HPV (hrHPV) by the Cobas 4800 HPV test. We estimated positive predictive values (PPV) and negative predictive values (NPV) and 95% confidence intervals (CI) for a subset of women (n = 700) who underwent cervical biopsy and cytology at the actual CASSIS visit. hrHPV was detected in 329 women (47%) with HerSwab and in 327 (46.7%) with physician sampling. Respective values for HPV16/18 were 119 (17%) and 121 (17.3%). On histology, 134 women had CIN1, 49 had CIN2, 48 had CIN3, 5 had CIN2/CIN3, and 3 had cancers. PPVs for CIN2+ of any hrHPV were 28% (95% CI, 23.2-33.1) and 29.7% (95% CI, 24.8-34.9) for HerSwab and physician samples, respectively. Corresponding values for HPV16/18 were 43.7% (95% CI, 34.6-53.1) and 43.8% (95% CI, 34.8-53.1). PPV of cytology (ASC-US+) was 26.6% (95% CI, 21.6-32.0). Corresponding NPVs (same order as PPVs) were 96.4% (95% CI, 93.9-98.1), 97.8% (95% CI, 95.6-99), 90.9% (95% CI, 88.2-93.1), 91% (95% CI, 88.4-93.2), and 94.7% (95% CI, 91.8-96.8). Our results confirm that HPV self-sampling has comparable performance with a physician-collected sample in detecting cervical lesions. HPV self-sampling has the potential to increase coverage in cervical cancer screening.